Pointer as bool (libsdl-org#7214)

src/SDL.c

@@ -557,7 +557,7 @@ int SDL_GetVersion(SDL_version *ver)
     static SDL_bool check_hint = SDL_TRUE;
     static SDL_bool legacy_version = SDL_FALSE;
 
-    if (ver == NULL) {
+    if (!ver) {
         return SDL_InvalidParamError("ver");
     }